Interviewed by Vicky Marlow January 17, 2008

1.) Hi Dr. Gross, can you please first start out by telling us how you got started with Hip Resurfacing and give us a little background on your experience as a surgeon. Where did you train for hip resurfacing? Who trained you? Did you continue your training after starting resurfacing?

I went to medical school and trained in orthopedics at Johns Hopkins Hospital, in Baltimore, MD. I took a Joint Replacement Fellowship for one additional year with Dr. William Bargar, one of the world’s foremost experts in custom joint replacement implants, in Sacramento CA. I have been in the private practice of Orthopedics at Midlands Orthopaedics as a joint replacement specialist in Columbia, SC for the last 15 years.

Photo: Dr. Gross

I learned to perform hemi-resurfacing during residency; but as many of the current leaders in the field of hip resurfacing, I had to train myself to perform total hip resurfacing 9 years ago. I have performed over 1500 metal-metal resurfacings to date.

I led the US based FDA study on hip resurfacing for Corin. This is the only implant so far that has gained full US FDA approval based on an American study. I was the surgeon developer of the BIOMET Recap/Magnum resurfacing and large metal-metal total hip system. I am the surgeon developer of the world’s first fully porous femoral component for metal-metal resurfacing, the porous Recap.

I have developed a minimally invasive posterior approach 3 years ago that I use routinely, in conjunction with a multimodal pain management system, and a comprehensive blood management program to maximimize the speed of recovery, while minimizing both pain and complications.

I lecture on the topic of hip resurfacing throughout the world. I have had over 100 surgeon visitors at my hospital to learn my techniques over the last several years. I do perform all of my own procedures with the help of my assistant Lee Webb N.P.; residents and fellows do not perform my cases. I primarily advance my knowledge and skill at this technique by research and critical analysis of my results, attending many of the major conferences, listening to the international experts on this topic, and teaching others about resurfacing.

Please see my website at grossortho.com for more details.

2.) Do you do the neck capsule preservation technique in your surgeries?

Yes. This technique applies to a posterior hip approach for resurfacing. I have always used a posterior approach. The theory is that if you preserve the soft tissue on the neck you will have fewer femoral neck fractures and cases of necrosis. I began using this capsule preservation technique 1 year ago, when we first started hearing a lot of publicity about it. It involves only a very minor alteration of technique. It is very simple to accomplish; so I figured, why not give it a try? There seems to be no downside. So far I have seen no change in my fracture rate of 1%. Necrosis typically shows up a little later after surgery, so it is too soon to say. My long term necrosis rate is 0.5 %. In another 2 years I will be able to publish a comparative study if the controversy is still around. At this point it seems to be mostly a promotional claim with no evidence behind it.

3.) Which approach do you prefer to use anteriolateral or posterior?

Posterior. There is no scientific evidence that one is better than the other. Even a direct comparative study by Mr. Ronan Treacy presented at the Annapolis Resurfacing Meeting in 2007 showed no difference. I think a surgeon should use the approach he/she is most comfortable with. In addition there are also some surgeons performing this operation through a direct lateral, direct anterior or a Transtrochanteric Ganz approach.

I personally prefer the posterior because I can get an excellent view of what I am doing routinely through a minimally invasive 4 inch incision. Return to activity is very rapid because the main abductor muscles are not cut. Only rare patients need formal PT. No patients retain a limp after 3 months.

4.) What is your opinion on the Direct Anterior approach for hip resurfacing, not the antero-lateral approach where the incision is on the side but the Direct Anterior approach?

This is rarely done. I suspect it is very difficult. If I were a patient, I would be hesitant to sign up for this until a surgeon has done over 100 resurfacings this way. Stemmed total hips don’t count; they are much easier to do through any approach.

5.) How long do you feel it takes for the bone to be fully healed, actually grow into the prosthesis?

Dog studies show that the process has already started by 6 weeks postop. I suspect 90% of ultimate strength has developed by 6 months and 100% by 1 year.

6.) Barring any complications, how many days in the hospital will a patient normally stay?

If they live within 4 hours of Columbia SC: 1 overnight; discharge about 5pm on the first postoperative day. All others: Discharge noon of postoperative day 2.

7.) What is your typical recovery time after resurfacing, what is your typical rehab protocol? 90 degree restriction? Walker” Crutches Cane? Amount of time? Blood thinners? TED stockings? Ice? PT

Please see my website grossortho.com for details.

Phase I: Walking and minor exercises for 6 weeks. Typically crutches for 1-2 weeks, followed by a cane for 1-2 weeks.

Phase II: Progressive walking and exercises between 6 weeks and 6 months.

Full return to all activities including running after 6 months.

Almost no one needs formal PT. Recovery from a posterior approach is not difficult. A lot more work may be required if the abductor muscles are impaired by a lateral or anterolateral approach.

For blood thinners I use Arixtra daily self administered injections for 10 days and baby aspirin for 1 month thereafter. With a minimally invasive technique, a rapid recovery program and the above anticoagulation regimen, I have had less than 0.5 % blood clots and no pulmonary emboli in 1500 cases. In the last 300 cases,I have not even had any blood clots.

I don’t use Ted stockings. They offer little benefit and make patients miserable. I wouldn’t wear thick nylons if they paid me.

Ice is an excellent adjunct for pain control in the first few days after surgery. Patients love it. I use an ice machine on everyone who likes it.

8.) How long before a typical patient is allowed to drive a car, return to work?

Drive 2-3 days after surgery. Deskwork or light physical work like a doctor, dentist in 2 weeks.
Work that requires you to be on your feet all day 6 weeks. Heavy lifting or sports can start at 6 months.

9.) What is the recommended time you tell your patients before they can start to run again/do impact sports? Are there any sports you don’t want your patients to participate in after surgery? Out of the patients you have resurfaced what are some of the sports they have returned to?

Golf and aerobic gym exercises at 6 weeks. Begin impact sports and running gradually at 6 months. Extreme activities such as competitive soccer, skydiving, double black diamond skiing, ice hockey with contact at 1 year. I have patients who have returned to virtually every sport.

10.) What is your take on cementless (femoral) devices for resurfacing?

I believe they are the future of resurfacing. At this point I am the only US Surgeon with experience using completely uncemented metal-on-metal resurfacings. I hear a lot of doubts and criticism from other surgeons. I’m used to this. I got the same when I started resurfacing 9 years ago. I am confident other surgeons will change their mind and follow my lead eventually. In the last year I have done over 300 fully porous resurfacings. Please see the addendum* if you are interested in reading further on this topic.

11.) Do you have a cut off age for resurfacing patients or do you go on a case by case basis?

My general rules are under 65 age, at least 2/3 of the femoral head viable, and enough socket intact to accept a component without screws. I estimate that almost 40% of all hip replacement patients in the US would qualify. The younger a patient is, the more I bend the other 2 rules to preserve bone stock with resurfacing. I sometimes perform difficult cases with custom implants in young patients.

12.) What type of anesthesia do you use general or epidural or ?

My comprehensive multimodal pain management program includes spinal anesthetic with a long acting narcotic as well as intravenous sedation. With this program in conjunction with minimally invasive surgery my patients have very little pain during their hospital stay. Most are able to sleep comfortably even the first night after surgery. Most patients are amazed by the lack of any serious pain. The days when patients were miserable with pain after surgery should be long gone. Unfortunately many surgeons have not yet embraced these principles, and their patients suffer needlessly. The only exception to this rule is the group of patients who are addicted to prescription narcotics before surgery. It is difficult to do as good a job with postoperative pain management in this group.

13.) Are there any cases that you will not take in particular, AVN, dysplasia, small cysts. Maybe touch on some of the very difficult cases you have been able to resurface.

I take on many patients who are higher risk for complication (such as AVN, dysplasia and large cysts) on an individualized basis. Many factors are considered. Small 1-3 cm cysts have not been a problem in my experience.

14.) Do you do bilateral surgeries same day, if not how far apart do you recommend?

I do bilateral surgery (only for patients with normal bone strength) on Monday followed by the second surgery on Wednesday. Patients are discharged on Friday at noon.
 
15.) What device do you prefer to use for hip resurfacing?

As the designing surgeon of the BIOMET Recap and Magnum system I have a strong bias towards my own work. I currently prefer the fully porous resurfacing system that I have pioneered. I will implant the hybrid version if a patient prefers.

16.) If you can’t perform a hip resurfacing – what THR device do you prefer and why?

BIOMET Magnum total hip (large bearing metal-on-metal) with a porous coated stem such as the Mallory. My design. Large bearings are stable, unbreakable and show very high wear resistance. They are the best alternative to Resurfacing.
Ceramics and “improved” (crosslinked PE) plastics are prone to dislocate because they employ small bearing sizes (as compared to metal-on-metal) and are susceptible to break with repetitive high impact. Ceramics have recently also been discovered to develop abnormal high wear states and squeaking in 1-5% of patients after several years of implantation.

17.) What do you consider an adequate number of surgeries for a doctor to be proficient at hip resurfacing?

Surgeon Talent varies tremendously, probably more so than athletic talent. The problem is that it is extremely hard for a non surgeon to evaluate who is best. Some have done large numbers and still are not particularly skilled. Some are good at writing research papers but are not so skilled at cutting. Unless you are a surgeon who knows the literature in this field and can watch several surgeons before they make a decision; I advise you to talk to a few patients who have had a particular surgeon work on them and base most of your decision on this “word of mouth” reputation.
Most reasonably talented Joint Replacement Fellowship trained orthopedic surgeons will probably be adequate after 100 Resurfacings; over 500 to be considered experienced.

18.) Can you explain how some devices like the Biomet are used when it is not FDA approved?

The Birmingham (Smith & Nephew, Richards) total HSR was the first to get FDA approval in the US based on an unprecedented FDA decision to approve this implant on the basis of single (developing) surgeon’s foreign data. Cormet 2000 ( Corin Ltd., Stryker) total HSR was the first to be approved based on the usual mechanism of a US run Multi-center FDA study( approval 7/2007, I was the lead investigator). Therefore, there are now 2 implants available in the US that have an FDA indication for total HSR.

The Recap/Magnum (Biomet), Conserve Plus (Wright Medical) and APR (Depuy) are all also FDA approved implants in the USA. They may be legally used by any surgeon for the purpose of total Hip Surface Replacement. (The FDA does not regulate how surgeons may use approved implants.) However, the implant companies may not promote them as total HSR devices. (The FDA does regulate how implant companies may market approved implants.)
Approximately 20 different companies sell total HSR implants on the worldwide market, including all of those mentioned above.

A specific use of an implant (or drug) that is approved by the FDA is termed an FDA approved indication. As soon as a company has received one indication for use of their implant (or drug), the implant (or drug) is FDA approved. The use of this same implant (or drug) for a purpose other than for the approved indication is termed an off–label use. Off-label use is legal. In fact, much of American medical practice involves off-label use of drugs and implants. It would be impossible for the FDA to regulate doctors’ practice in every situation. Actually the Supreme Court has expressly stated that this is not the FDA role (see Rehnquist opinion).

Many insurance companies do have contract clauses that deny payment for “experimental” treatment. How to define what is experimental is very controversial. However, “experimental” is something altogether different than off-label use of implants and drugs.

Therefore, an insurance company would be treading on thin ice if they were to use FDA indications as a basis to deny payment.

*ADDENDUM:
Should you have uncemented hip resurfacing?